mkmf.rb

Returns the size of the given type. You may optionally specify additional headers to search in for the type.

If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with ‘SIZEOF_’, followed by the type name, followed by ’=X’ where ‘X’ is the actual size.

For example, if check_sizeof(‘mystruct’) returned 12, then the SIZEOF_MYSTRUCT=12 preprocessor macro would be passed to the compiler.

Generates a header file consisting of the various macro definitions generated by other methods such as have_func and have_header. These are then wrapped in a custom ifndef based on the header file name, which defaults to ‘extconf.h’.

For example:

   # extconf.rb
   require 'mkmf'
   have_func('realpath')
   have_header('sys/utime.h')
   create_header
   create_makefile('foo')

The above script would generate the following extconf.h file:

   #ifndef EXTCONF_H
   #define EXTCONF_H
   #define HAVE_REALPATH 1
   #define HAVE_SYS_UTIME_H 1
   #endif

Given that the create_header method generates a file based on definitions set earlier in your extconf.rb file, you will probably want to make this one of the last methods you call in your script.

Generates the Makefile for your extension, passing along any options and preprocessor constants that you may have generated through other methods.

The target name should correspond the name of the global function name defined within your C extension, minus the ‘Init_’. For example, if your C extension is defined as ‘Init_foo’, then your target would simply be ‘foo’.

If any ’/’ characters are present in the target name, only the last name is interpreted as the target name, and the rest are considered toplevel directory names, and the generated Makefile will be altered accordingly to follow that directory structure.

For example, if you pass ‘test/foo’ as a target name, your extension will be installed under the ‘test’ directory. This means that in order to load the file within a Ruby program later, that directory structure will have to be followed, e.g. "require ‘test/foo’".

The srcprefix should be used when your source files are not in the same directory as your build script. This will not only eliminate the need for you to manually copy the source files into the same directory as your build script, but it also sets the proper target_prefix in the generated Makefile.

Setting the target_prefix will, in turn, install the generated binary in a directory under your Config::CONFIG[‘sitearchdir’] that mimics your local filesystem when you run ‘make install’.

For example, given the following file tree:

   ext/
      extconf.rb
      test/
         foo.c

And given the following code:

   create_makefile('test/foo', 'test')

That will set the target_prefix in the generated Makefile to ‘test’. That, in turn, will create the following file tree when installed via the ‘make install’ command:

   /path/to/ruby/sitearchdir/test/foo.so

It is recommended that you use this approach to generate your makefiles, instead of copying files around manually, because some third party libraries may depend on the target_prefix being set properly.

The srcprefix argument can be used to override the default source directory, i.e. the current directory . It is included as part of the VPATH and added to the list of INCFLAGS.

Sets a target name that the user can then use to configure various ‘with’ options with on the command line by using that name. For example, if the target is set to "foo", then the user could use the —with-foo-dir command line option.

You may pass along additional ‘include’ or ‘lib’ defaults via the idefault and ldefault parameters, respectively.

Note that dir_config only adds to the list of places to search for libraries and include files. It does not link the libraries into your application.

Tests for the presence of an —enable-config or —disable-config option. Returns true if the enable option is given, false if the disable option is given, and the default value otherwise.

This can be useful for adding custom definitions, such as debug information.

Example:

   if enable_config("debug")
      $defs.push("-DOSSL_DEBUG") unless $defs.include? "-DOSSL_DEBUG"
   end

Searches for the executable bin on path. The default path is your PATH environment variable. If that isn‘t defined, it will resort to searching /usr/local/bin, /usr/ucb, /usr/bin and /bin.

If found, it will return the full path, including the executable name, of where it was found.

Note that this method does not actually affect the generated Makefile.

Instructs mkmf to search for the given header in any of the paths provided, and returns whether or not it was found in those paths.

If the header is found then the path it was found on is added to the list of included directories that are sent to the compiler (via the -I switch).

Returns whether or not the entry point func can be found within the library lib in one of the paths specified, where paths is an array of strings. If func is nil , then the main() function is used as the entry point.

If lib is found, then the path it was found on is added to the list of library paths searched and linked against.

Returns where the static type type is defined.

You may also pass additional flags to opt which are then passed along to the compiler.

See also have_type.

Returns whether or not the constant const is defined. You may optionally pass the type of const as [const, type], like as:

  have_const(%w[PTHREAD_MUTEX_INITIALIZER pthread_mutex_t], "pthread.h")

You may also pass additional headers to check against in addition to the common header files, and additional flags to opt which are then passed along to the compiler.

If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with ‘HAVE_CONST_’.

For example, if have_const(‘foo’) returned true, then the HAVE_CONST_FOO preprocessor macro would be passed to the compiler.

Returns whether or not the function func can be found in the common header files, or within any headers that you provide. If found, a macro is passed as a preprocessor constant to the compiler using the function name, in uppercase, prepended with ‘HAVE_’.

For example, if have_func(‘foo’) returned true, then the HAVE_FOO preprocessor macro would be passed to the compiler.

Returns whether or not the given header file can be found on your system. If found, a macro is passed as a preprocessor constant to the compiler using the header file name, in uppercase, prepended with ‘HAVE_’.

For example, if have_header(‘foo.h’) returned true, then the HAVE_FOO_H preprocessor macro would be passed to the compiler.

Returns whether or not the given entry point func can be found within lib. If func is nil, the ‘main()’ entry point is used by default. If found, it adds the library to list of libraries to be used when linking your extension.

If headers are provided, it will include those header files as the header files it looks in when searching for func.

The real name of the library to be linked can be altered by ’—with-FOOlib’ configuration option.

Returns whether or not macro is defined either in the common header files or within any headers you provide.

Any options you pass to opt are passed along to the compiler.

Returns whether or not the struct of type type contains member. If it does not, or the struct type can‘t be found, then false is returned. You may optionally specify additional headers in which to look for the struct (in addition to the common header files).

If found, a macro is passed as a preprocessor constant to the compiler using the member name, in uppercase, prepended with ‘HAVE_ST_’.

For example, if have_struct_member(‘struct foo’, ‘bar’) returned true, then the HAVE_ST_BAR preprocessor macro would be passed to the compiler.

Returns whether or not the static type type is defined. You may optionally pass additional headers to check against in addition to the common header files.

You may also pass additional flags to opt which are then passed along to the compiler.

If found, a macro is passed as a preprocessor constant to the compiler using the type name, in uppercase, prepended with ‘HAVE_TYPE_’.

For example, if have_type(‘foo’) returned true, then the HAVE_TYPE_FOO preprocessor macro would be passed to the compiler.

Returns whether or not the variable var can be found in the common header files, or within any headers that you provide. If found, a macro is passed as a preprocessor constant to the compiler using the variable name, in uppercase, prepended with ‘HAVE_’.

For example, if have_var(‘foo’) returned true, then the HAVE_FOO preprocessor macro would be passed to the compiler.

Tests for the presence of a —with-config or —without-config option. Returns true if the with option is given, false if the without option is given, and the default value otherwise.

This can be useful for adding custom definitions, such as debug information.

Example:

   if with_config("debug")
      $defs.push("-DOSSL_DEBUG") unless $defs.include? "-DOSSL_DEBUG"
   end